According to the doppler effect what appears to happen when a light source moves further away from an observer

a. the wave lengthens and frequency appears to increase

b. the elevtromagnrtic waves appear more red in color

c. the waves compress and the frequency appears to increase

d. the electromagnetic waves appear more blue in color

The correct answer is B. "the electromagnetic waves appear more red in color".

Explanation:

Scientists use the Doppler effect to understand the universe by determining the motion of the object.

Red shift: The apparent frequency of light decreases as the source object in space moves away from us.  The light is shifted to red end. The apparent frequency decreases and there is increase in the wavelength of the light.

Blue shift: The apparent frequency of light increases as the object in space moves towards us. The light is shifted to blue end. In this case, there is decrease in the wavelength of the light.  The frequency of the wave increases.

In the given problem, when the light source moves further away from an observer, the electromagnetic waves appear red in color.

Therefore, the correct option is (B).

Hello there!

When the source of light moves further away from the observer (or the observer moves further away from the light source), there is something called "redshift"

The observer sees the wavelength wider, which means that the frequency decreases. This phenomenon causes a shift in the color of the wave, which now looks more red.